Pourriat J L, Lamberto C, Fosse J P, Vasseur B, Cupa M
Département d'Anesthésie-Réanimation, Hôpital Avicenne, Paris, France.
Chest. 1989 Feb;95(2):364-9. doi: 10.1378/chest.95.2.364.
We investigated the effect of small inspiratory resistive loads on the breathing patterns of patients with COPD admitted to the ICU for acute respiratory failure. Patients were in stable clinical condition three days after weaning from the acute-phase ventilation. Healthy nonsmokers served as controls. Breathing patterns were recorded for 20-min periods during unloaded breathing (R0), then with small inspiratory resistive loads (R1 = 2.5 cmH2O L/s and R2 = 5.2 cmH2O L/s) applied in random order. Respiratory parameters were memorized in real time and blood gases measured continuously with a transcutaneous PO2/PCO2 monitor and compared periodically with arterial blood gases. Minute volume (VE) and respiratory rate decreased with no modification in blood gas values. In the COPD patients, R1 was too small to be perceived; when R2 was applied, no increase in TI was observed, and VT and VT/TI decreased. The VE could not be maintained despite a shortening of expiratory time. The COPD patients did not have significant increase of occlusion pressure (P0.1). Mean blood gas values did not change during the testing, but the coefficient of variation of tcPCO2 increased. During the critical period following weaning from artificial ventilation, COPD patients did not respond in the same manner as normal subjects to inspiratory resistive loads, but did not have modified gas exchange during the 20-min period.
我们研究了小吸气阻力负荷对因急性呼吸衰竭入住重症监护病房（ICU）的慢性阻塞性肺疾病（COPD）患者呼吸模式的影响。在患者从急性期通气撤机三天后，其临床状况稳定。健康非吸烟者作为对照。在无负荷呼吸（R0）期间记录20分钟的呼吸模式，然后以随机顺序施加小吸气阻力负荷（R1 = 2.5 cmH₂O L/s和R2 = 5.2 cmH₂O L/s）。实时记录呼吸参数，并用经皮PO₂/PCO₂监测仪连续测量血气，并定期与动脉血气进行比较。分钟通气量（VE）和呼吸频率下降，而血气值无改变。在COPD患者中，R1太小以至于无法感知；当施加R2时，未观察到吸气时间（TI）增加，潮气量（VT）和VT/TI下降。尽管呼气时间缩短，但VE无法维持。COPD患者的阻断压（P0.1）没有显著增加。测试期间平均血气值没有变化，但经皮二氧化碳分压（tcPCO₂）的变异系数增加。在从人工通气撤机后的关键时期，COPD患者对吸气阻力负荷的反应与正常受试者不同，但在20分钟内气体交换没有改变。
